Not really a crash but there are some serious troubles with the OSX PPC version.
The first oddity is the DMG distribution image disk that contains an executable (bundle) without the usual green "S" icon, completely blank.
The executable itself does nothing, I can only see the title "ScummVM" in the top menu bar and the mouse pointer disappear (like it was behind the backdrop).
No menus, no dialog window, nothing. Also I can't quit the application, the only way it is to force the task to be killed through the usual ALT+CMD+ESC key combination.
I am on a PowerMac G4 MDD with latest OSX 10.5.8 installed, Radeon X800XT and 2 Gig of System memory.
I have also tried to built the executable (bundle) from source with identical results, no icon, no windows, nothing.

The PPC version becomes harder to generate with each release, at least for me, and I almost didn't make one for this release. The only system I have to test it is a Mac OS X 10.6 intel iMac, which means it uses Rosetta to run the PPC executable. This is far from ideal. This latest release works properly for me (and I do have the icon), but I am not really surprised that others have issue with it.

Most of the missing MacPorts packages for PPC are (unofficially) available thanks to a bunch of enthusiast that still support this platform.
For example SDL2 and Flac (needed for ScummVM build) exists natively for OSX PPC but not so up to date, SDL2 is hold on 2.0.3 (most recent is 2.0.10) and flac to 1.3.2 (latest 1.3.3) thanks to a developer named "Kencu" and his unvaluable work in PPC porting to old OSX systems named "TigerPorts", the link to the repository is the following:

I prefer to compile the PPC binaries natively on PowerMacs instead of cross-compiling on intel Macs because the results are more predictable on the real hardware. I can provide some support for OSX PPC version of ScummVM with debug reports but since I am not a programmer I need some hints on how to proceed. I have already done this in the past for other projects like the Amiga emulator FS-UAE ported to PPC Macs so I can borrow some spare time to help in mantaining this wonderful project.
I am addicted to adventure games since the very first Apple II releases so I followed ScummVM almost since the very first day and even if I have a modern MacPro for my everyday activity I like to play vintage games on vintage hardware

I am wondering if with the software getting bigger with each release we might have hit some kind of limits in the executable size or stack memory usage on PPC macs. One thing you could try is to compile ScummVM with just one (or a few engines) and see if the application then opens properly (for example use the --disable-all-engines --enable-engines=scumm,scumm_7_8,he,sci,sci32 flags with configure to enable only the scumm and sci engines).

Richtw: Not sure what is going on, but you would need to run the latest nightly under a debugger such as https://lldb.llvm.org/ and then get a backtrace if it is an OS level crash or at least some level of debug information to help pinpoint what is causing the issue.

I tested your dropbox version and it does now work on my G5 desktop. But...the "S" icon for the app is still missing. Strangely, the icon does appear in the "properties" window when viewing the applications properties.